Species
+

Deutzia gracilis Siebold & Zucc.

Japanese snowflower, Slender deutzia, Slender pride of Rochester (EN), Slender pride of rochester

Climate known 52 photographs
Add one to my plants Sow seed

Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.

Summary

Deutzia gracilis, the slender deutzia or Japanese snow flower, is a species of flowering plant in the hydrangea family Hydrangeaceae, native to Japan.

Text from Wikipedia, “Deutzia gracilis”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Deutzia

Deutzia is a genus of about 60 species of flowering plants in the family Hydrangeaceae, native to eastern and central Asia, and Central America and also Europe. By far the highest species diversity is in China, where 50 species occur.

Text from Wikipedia, “Deutzia”, CC BY-SA 4.0, quoted as written.

Family
Hydrangeaceae
Described by
Siebold & Zucc.
Native to
Japan
Wild records
975 in range· 919 open

At a glance

Warmest month
27°C
Aug, mean day; nights 20 °C (CHELSA)
Rain
2018mm/yr
12 wet months · peak Sep 272 mm (CHELSA)
Light
16–34DLI
mol/m²/day, winter to summer, open sky (CHELSA shortwave)
In short condensed by rule from the cultivation cards · not written by a person
Rain rule: a summer growing season, March and May to October in the northern hemisphere (March and May to October at the habitat, northern). Habitat rain 2018 mm a year, wettest September at 272 mm, driest December at 64 mm (habitat calendar, northern hemisphere). Open sky over the habitat: 16 to 34 mol/m²/day. Cold floor -4.2 °C (1st-percentile habitat night, NASA POWER).
Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Also known as Deutzia gracilis f. albomarmorata (Lemoine) C.K.Schneid.; Deutzia gracilis f. aurea Schelle; Deutzia gracilis f. aurea Schelle ex C.K.Schneid.; Deutzia gracilis f. aureomarginata (Lemoine) C.K.Schneid.; Deutzia gracilis f. pilifera Honda and 11 more.

Cultivation

Its year Rain rule: a summer growing season, March and May to October in the northern hemisphere (March and May to October at the habitat, northern).

This species’ habitat figures, and what two fixed rules read from them.

The rain rule reads a summer growing season: 70% of the year's rain (1523 mm of 2018 mm) falls in March and May to October, warmer than the year (wet-season mean 17.3 °C against a yearly mean of 12.1 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to April and September.

Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve gives a season to reverse. A reading of the curves, not an observation of the plant.

Rain Habitat rain 2018 mm a year, wettest September at 272 mm, driest December at 64 mm (habitat calendar, northern hemisphere).

This species’ habitat figures, with their source.

2018 mm a year at the habitat, 1523 mm of it March and May to October. Wettest month September at 272 mm, driest December at 64 mm. Across the envelope cells the year's total runs 1420 mm to 3188 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, northern hemisphere).

CHELSA monthly precipitation, median year across the envelope cells. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light Open sky over the habitat: 16 to 34 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 16 to 34 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 14, the highest 90th-percentile month 36).

CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Warmth and air Cold floor -4.2 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is -4.2 °C, the absolute minimum -10.0 °C, about 68 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 28.9 °C. Monthly means: coldest night -4.4 °C in January (across the envelope cells -10.6 °C to 0.9 °C), warmest day 26.6 °C in August (median year across the envelope cells, CHELSA). Cold floor: -4.2 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).

NASA POWER daily minima and maxima 1981–2024 at the typical cell, lapse-corrected to its elevation; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity

Relative humidity at the habitat: 58 to 68% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.

CHELSA relative humidity, median year across the envelope cells.

The figures the cards read from are in Climate below, and where they came from in Natural habitat.

Climate across the habitat

Habitat climate through the yearMean day from 4 °C in Jan to 27 °C in Aug; mean night from -4 °C in Jan to 20 °C in Aug. The cold quarter, Dec to Feb, is the three months around the coldest night. 2018 mm of rain a year, most in Sep. The bands show the 10th to 90th percentile across 652 habitat cells. Over 44 years at the typical cell the absolute minimum was -10.0 °C and the 99th-percentile day 28.9 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.-20°-10°10°20°30°frost28.9° 99th-percentile day (undated)-10.0° lowest night in 44 yrs (undated)°C · day and nightcold quarter0100200300400500mm rainDLI 16–34RH 58–68 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 652 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C4 / -1–85 / -0–88 / 4–1214 / 10–1719 / 15–2122 / 19–2425 / 22–2827 / 23–2923 / 19–2518 / 14–2012 / 8–157 / 2–10
Night °C-4 / -11–1-4 / -10–1-1 / -6–45 / 1–910 / 6–1415 / 11–1819 / 15–2220 / 16–2316 / 12–2010 / 6–144 / -1–9-1 / -7–4
Rain mm74 / 40–24791 / 45–187154 / 83–226150 / 95–238177 / 122–289232 / 160–398266 / 173–415232 / 148–338272 / 203–399190 / 125–258116 / 66–23664 / 37–239
DLI18 / 15–2023 / 21–2528 / 25–3033 / 31–3534 / 32–3631 / 28–3431 / 28–3432 / 29–3425 / 22–2721 / 19–2417 / 15–1916 / 14–18
RH %59 / 55–6558 / 55–6459 / 57–6259 / 57–6161 / 59–6466 / 63–6968 / 65–7067 / 63–7066 / 63–6963 / 60–6561 / 58–6359 / 55–64

Each figure is the median across the 652 grid cells holding the 964 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 1091:6292 (35.425, 134.625). Over 44 years there: absolute minimum -10.0 °C, 1st-percentile night -4.2 °C, 99th-percentile day 28.9 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 652 distinct grid cells holding the 964 in-range records; extremes and elevation at the typical cell 1091:6292 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 35.50_134.375, lapse-corrected +413 m at 6.5 °C/km. Elevation: ETOPO 2022, 655 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeJapan· introduced: Germany, China North-Central, China Southeast, Alabama, Georgia, Maryland
Kew's description“shrub” · “temperate”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker35.79, 138.91 · in the densest population, 623 records (64% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 975 georeferenced records inside the native range; the map shows only the 919 openly licensed ones, which alone would put the marker 3 km away. 303 records outside the range (gardens, roadsides, misidentifications) ignored. 11 in-range records are placed to worse than 10 km and stay on the map but off the climate.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population of the 975 in-range records; it decides nothing.

Photographs

Deutzia gracilisDeutzia gracilisDeutzia gracilisDeutzia gracilisDeutzia gracilisDeutzia gracilisDeutzia gracilisDeutzia gracilis

Photographs: (c) Marco Mussita, some rights reserved (CC BY) (4); no rights reserved · CC0 (3); (c) harum.koh, some rights reserved (CC BY-SA).

Photographs: iNaturalist did not answer when this page was built; what is shown came from the sources that did.

Papers naming this species

Works whose title or abstract names Deutzia gracilis, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Use of Spent Mushroom Substrate for Growing Containerized Woody Ornamentals: An Overview
Calvin Chong, Danny Lee Rinker (1994) · Compost Science & Utilization
Growth and Mineral Nutrient Status of Containerized Woody Species in Media Amended with Spent Mushroom Compost
Calvin Chong, R. A. Cline, Danny Lee Rinker, O. B. Allen (1991) · Journal of the American Society for Horticultural Science
Container-grown Ornamental Plant Growth and Water Runoff Nutrient Content and Volume Under Four Irrigation Treatments
Aaron L. Warsaw, R. Thomas Fernandez, Bert M. Cregg, Jeffrey A. Andresen (2009) · HortScience
Response of Four Container Grown Woody Ornamentals to Immature Composted Media Derived from Waxed Corrugated Cardboard
D.A. Raymond, Calvin Chong, R. P. Voroney (1998) · Compost Science & Utilization
Caractérisation de la l-thréo-β-hydroxyleucine à partir de Deutzia gracilis
J. Jadot, J. Casimir, F. C. Alderweireldt (1963) · Biochimica et Biophysica Acta
Séparation et caractérisation d'une hydroxyleucine à partir de Deutzia Gracilis
J. Jadot, J. Casimir (1961) · Biochimica et Biophysica Acta
Notes on the powdery mildews (Erysiphaceae) in Iran.
M. Abbasi, J Boujari, M. Donyadost-Chalan (2013) · Bīmārīhā-yi giyāhī (Online)/Bīmārīhā-yi giyāhī (Print)
Occurrence Download
GBIF.org User (2026) · Global Biodiversity Information Facility
Occurrence Download
GBIF.org User (2026) · Global Biodiversity Information Facility
Occurrence Download
GBIF.org User (2026) · Global Biodiversity Information Facility

Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.

Other Deutzia 2 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-20; this build: skipped
inat.taxon not askedcarried from build of 2026-09-20 (rederive)
inat.photos.wild answeredcarried from build of 2026-09-20; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-20; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 115 datasets via GBIF.org; each carries its own licence.